The ideal daytime temperature for cotton production is 82 degrees
Fahrenheit. The plant also needs an adequate supply of water. In Arizona and
other cotton-producing areas, daytime temperatures often exceed 100 degrees F.
Plant physiologists Salvucci and Crafts-Brandner have found that high
temperatures can adversely affect the function of a plant enzyme called Rubisco
activase, resulting in impaired photosynthesis and reduced yields.

At the ARS
Western
Cotton Research Laboratory in Phoenix, the scientists observed how Rubisco
activase from plants adapted to various climates functioned at high
temperatures. They discovered that the enzyme from plants adapted to the hot
Arizona desert worked much better at high temperatures, compared to the enzyme
from plants adapted to cold climates.

The research provides a scientific basis for improving the enzyme in crop
plants such as cotton. The team is testing the hypothesis that plants
engineered to contain Rubisco activase from a shrub adapted to the hot Arizona
desert will perform more efficiently at high temperatures.

If successful, the research could improve the production of cotton in
Arizona and across the U.S. Cotton Belt, and perhaps improve the performance of
other crops that suffer from high temperatures.

Read
more about the research in the November 2004 issue of Agricultural
Research magazine.